CAMBRIDGE, Mass. — The former National Security Agency contractor Edward Snowden said Thursday that he planned to help develop a modified version of Apple’s iPhone for journalists who are concerned that they may be the target of government surveillance.

The announcement was made during a one-day conference on “Forbidden Research” at the Massachusetts Institute of Technology’s Media Lab.

Snowden, who spoke via a video connection from Russia, where he is living in exile, said he was working with Andrew Huang, a computer hacker known as Bunnie who studied electrical engineering at MIT, to see if it would be possible to modify a smartphone to alert journalists working in dangerous environments to electronic surveillance.

Snowden, who is a board member of a nonprofit group called the Freedom of the Press Foundation, said he was concerned that cellphones and smartphones serve as tracking devices that automatically create electronic dossiers that give third parties, including governments, detailed information on location.

As an example of the dangers of location data, he cited the mortar attack in 2012 by the Syrian government that killed Marie Colvin, an American journalist who was reporting in Homs, Syria, for The Sunday Times of London.

“The radio frequency emissions of her communications that she used to file those news reports were intercepted by the Syrian army,” Snowden said.

He said it was increasingly difficult for users to trust their smartphones. They may be tampered with by malware programs, causing them to transmit location information even when the user may think that the device has been placed into a safe “airplane mode.”

Huang said the project was still experimental, but he hoped it would provide journalists with modified phones that would come in a special case with a separate display that would provide an alert when the phone was active and transmitting data at improper times.

The conference focused on issues raised by computer hacking, as well as controversial scientific research in areas such as genetic engineering and geoengineering.

Also at the conference, Reid Hoffman, one of the founders of LinkedIn, which recently agreed to be acquired by Microsoft for $26 billion, announced that he planned to offer a $250,000 “Disobedience Prize” aimed at promoting positive social change and opposing injustice.

“It will go to a person or group engaged in what we believe is excellent disobedience for the benefit of society. The disobedience that we would like to call out is the kind that seeks to change society in a positive way, and is consistent with a set of key principles,” wrote Joichi Ito, director of the MIT Media Lab, in a web posting about the prize. The timing of the award has not yet been determined.

In separate panels, biologists and climate scientists explored the risks and rewards of scientific research that might have unexpected consequences.

Kevin Esvelt, a biologist who is director of the Sculpting Evolution research group at the MIT Media Lab, spoke about new, easily accessible genetic engineering technologies that might be used to preserve species that are at risk of extinction, and alternatively to eradicate pests that threaten human populations by spreading disease.

He described a discussion scientists had on Wednesday with residents of Martha’s Vineyard about the use of advanced genetic engineering techniques to introduce a type of mouse that had been modified to be unable to carry Lyme disease. The idea would be to break the transmission of the disease to ticks and then to humans.

He said that before beginning the experiment, the scientists engaged the community to discuss potential risks.

Scientists on several panels acknowledged that it was impossible to be certain about unforeseen effects from new engineering techniques.

“What we’re worried about is something that we do that could be very attractive in the short term but have some triggering mechanism or some slow events that occur far in the future,” said George Church, a Harvard geneticist who is exploring genetic engineering techniques to revive extinct species.